Zinc
Plus Antibiotic Reduces Treatment Failure in Infants
Joe
Barber Jr, PhD
May
31, 2012 — Infants with probable serious bacterial infection who received zinc
in addition to standard antibiotic therapy were less likely to suffer treatment
failure, according to the findings of a randomized, double-blind, placebo-controlled
trial.
Shinjini
Bhatnagar, PhD, from the All India Institute of Medical Sciences in New Delhi
and the Translational Health Science and Technology Institute in Gurgaon,
Haryana, India, and colleagues published their findings online May 31 and in the
June 2 print issue of the Lancet.
The
authors state that the current treatments for infants with severe infections
are less than optimal. "Despite advances in antimicrobial treatment,
outcomes remain poor," the authors write. "Development of inexpensive
and accessible interventions that could improve treatment outcomes and reduce
case fatality is important."
To
assess the effect of zinc supplementation on treatment success, Dr. Bhatnager
and colleagues screened infants aged from 7 to 120 days at 3 hospitals in New
Delhi between July 6, 2005, and December 3, 2008, for convulsions, fast
breathing, severe chest indrawing, and other signs of serious bacterial
infection. They then randomly assigned 700 patients to receive either zinc (352
patients, 332 assessed for treatment failure) or placebo (348 patients, 323
assessed for treatment failure) in addition to standard antibiotic care
(ampicillin and an aminoglycoside, third-generation cephalosporin and an
aminoglycoside, or intravenous cloxacillin). Overall, the investigators saw a
40% reduction in the risk for treatment failure in the zinc supplementation
group compared with the placebo group (95% confidence interval [CI], 10% - 60%;
P = .0113).
The
researchers included preterm infants (gestational age ≤ 32 weeks) who were
older than 2 months at screening. They excluded infants weighing 1500 g or
less; those requiring mechanical ventilation, inotropic drugs, or exchange
transfusion; those with any serious underlying medical condition; those born to
HIV-infected mothers; and those who received zinc during the present infective
episode. The primary outcome of the trial was treatment failure (defined as a
need to change antibiotics within 7 days of randomization, a need for intensive
care, or death at any time within 21 days after randomization); the secondary
outcomes included clinical time to recovery, time to achieve exclusive oral
feeding, time to weight gain, and time to overall recovery.
No
differences were observed in the baseline characteristics of the placebo and
zinc supplementation groups. In a subgroup of patients aged from 7 to 60 days,
zinc supplementation reduced the incidence of treatment failure by 54% (95% CI,
20% - 74%; P = .0045).
Zinc
had a greater effect in infants with diarrhea than in those without diarrhea
(risk ratio [RR], 0.85 [95% CI, 0.52 - 1.39] vs 0.31 [95% CI, 0.14 - 0.65],
respectively; P = .0260), but no difference in treatment efficacy was
observed between underweight and nonunderweight patients (RR, 0.46 [95% CI,
0.21 - 0.98] vs 0.68 [95% 0.43 - 1.08], respectively; P = .0378).
However,
the researchers caution that additional research is necessary before zinc can
be applied clinically to prevent treatment failure. "Future trials need to
measure the efficacy of zinc treatment for probable serious bacterial infection
in other settings — specifically, other studies should measure the effect of
zinc supplementation on important outcomes in children who are diagnosed with serious
bacterial infections without measurements of concentrations of C-reactive
protein," the authors write. "If such trials show improvement in
treatment outcomes, the use of zinc as an adjunct to antibiotic treatment might
lead to substantial reductions in infant mortality, particularly in
resource-constrained settings where second-line antibiotics and appropriate
intensive care might be unavailable."
In
a related commentary, Christa L. Fischer Walker, PhD, MHS, and Robert E. Black,
MD, MPH, say they are encouraged by these findings but agree that additional
research is necessary. "Bhatnagar and colleagues' promising results will
need to be replicated before practical recommendations can be made," Dr.
Fischer Walker and Dr. Black write. "The exact mechanism for the effect of
supplemental zinc is unknown and needs further investigation, but the clinical
benefits in diarrhoea and pneumonia in children younger than 5 years, and now
in probable serious infections in young infants, suggest that therapeutic use of
zinc could have wide application."
The
authors and commentators have disclosed no relevant financial relationships.
Lancet.
Published online May 31, 2012.
Medscape Medical News © 2012 WebMD,
LLC